Q: My 9- and 13-year-old sons used to be best friends. Since my older son became a teenager, he no longer wants to have anything to do with his younger brother. He has pushed him away when he tries to followhim, called him names and has been mean to him. What can I do? My younger son doesn't understand and is really upset.

A: It is not unusual that your older son may be wanting to spend less time with his younger brother, the Help for Families panel says.

Your older son is changing developmentally as he gets to a certain age and place in life, says panelist Michael Daniels.

"Have a private discussion with the 13-year-old," he says. "Tell him you notice a difference in the way he treats his brother. Talk in a nonconfrontational way, although he will probably get defensive anyway. Family development causes stress for everyone."

He adds that the younger boy probably looked up to and idolized his older brother.

"Now he's feeling rejection," Daniels says. "The 9-year-old needs to develop ego strength. You need to help build him up and explain how life changes as you get older and he will be different when he is 13."

However calling him names is not nice, says panelist Pam Wallace.

Talk to the older boy about how he treats people, Wallace says.

"There is no call to be mean," she says. "That's not what we do when we are around other. Tell him, We are family and you will be brothers forever. If you don't want to do kid stuff, that's fine, you still have to treat him well."

Daniels recommends talking to the two boys separately.

"Ask the 13-year-old to remember what life felt like as a 9-year-old," he suggests.

Panelist Chad Stefanyak asks how the older boy is treating his brother in front of his friends.

"He is setting a standard as how others can treat his brother," Stefanyak says. "He could be setting him up for bullying."

The older boy needs to think about what message he is giving his friends, agrees Daniels.

He adds that relationships between siblings often change over time.

"There are lots of brothers who fought all the time as kids and are now best friends," he says.

Also he asks: How do you as parents talk to the 9-year-old versus how you talk to the 13-year-old? Perhaps the older boy is picking up on something.

And Daniels asks: How do you and your spouse treat each other?

When you resolve conflicts, you are modeling how your kids learn to deal with conflict, he says.

Also try to build family bonds by doing things together on a regular basis, Daniels says.

Also encourage the boys to spend time doing something they both enjoy together on a regular basis, says panelist Rhoda Stoudt.